This invention relates to antiinflammatory substituted-thio diaryl imidazoles.
2,3,5,6-Tetrahydro-6-phenylimidazole-[2,1-b]thiazole (Levamisole) has shown clinical efficacy as an antiarthritic. Levamisole was inactive in an adjuvant arthritis test, however, and its human efficacy is believed to be a result of its immunological activity.
2-Alkylthio-4-arylimidazolines are known in the literature. J. Prakt. Chem., 318, 168 (1976) discloses 4,5-diphenyl-4,5-dihydro-1H-imidazole-2-thiol and its S-carboxymethyl derivative. U.S. Pat. No. 4,153,706 (Smith Kline) discloses 6-hydroxy-5,6-diaryl-2,3,5,6-tetrahydroimidazo[2,1-b]thiazoles and their antiarthritic activity.
There is a continuing need for safe and effective antiinflammatory agents. Inflammation is a disease process characterized by redness, fever, swelling and pain. Arthritis, in its various forms, is the most prevalent, chronic, and severe of the inflammatory diseases. Traumatic injury and infection also involve inflammation, and antiinflammatory drugs are often used in their treatment. The usefulness of most commercial antiinflammatories is limited because of toxicity and adverse side-effects. Many produce gastric irritation and other effects, such as change in blood cells and central nervous system. Adreno-cortical steroids produce gastric irritation and suppression of normal adrenal function.
The present invention results from efforts to develop new antiarthritic compounds with good antiinflammatory activity and minimal side effects that could be more effective in treating arthritis than presently available drugs.